The former Olympian Oscar Pistorius was released from his South African prison this past Monday, October 19th, after only serving almost one year or about 20% of his sentence. He is being allowed to serve the remainder 4 years of his sentence under house arrest.
Compare this to the United States Federal Prison system. If anyone is jailed within the U.S. they are required to serve at lease 85% of their sentence within the prison. A 60-month sentence, such as his, would have been eligible for house arrest after serving 51 months.